Method of preventing precipitation of a reactive substance-bound microparticle, and reagent containing the micro particle

Abstract

According to the present invention, precipitation of a reactive substance-bound microparticle can be prevented in a dispersion liquid, to make a concentration of the reactive substance-bound microparticle uniform in the dispersion liquid. The present invention provides a method of preventing precipitation of a reactive substance-bound microparticle. The method includes coexisting at least one selected from the group consisting of polyanion or its salt, dextran, cyclodextrin, polyethylene glycol, and glycerol, with the microparticle in a dispersion liquid.

1 . A method of preventing precipitation of a reactive substance-bound microparticle, comprising:
 coexisting at least one selected from the group consisting of polyanion or its salt, dextran, cyclodextrin, polyethlyene glycol, and glycerol with the microparticle in a dispersion liquid.   
     
     
         2 . The method of  claim 1 , wherein the dispersion liquid contains polyanion or its salt at 0.3 to 5 percent by weight, dextran at 0.1 to 5 percent by weight, cyclodextrin at 0.1 to 5 percent by weight, polyethylene glycol at 0.3 to 5 percent by weight, or glycerol at 5 to 40 percent by weight. 
     
     
         3 . The method of  claim 1 , wherein the polyanion or its salt is a water-soluble, sulfate group-containing polymer compound. 
     
     
         4 . The method of  claim 3 , wherein the polyanion is dextran sulfate or heparin. 
     
     
         5 . The method of  claim 1 , wherein the reactive substance-bound microparticle is a colloidal gold particle to which an antibody or antigen is bound. 
     
     
         6 . A reagent comprising a reactive substance-bound microparticle and at least one compound selected from the group consisting of polyanion or its salt, dextran, cyclodextrin, polyethylene glycol, and glycerol,
 wherein precipitation of the microparticle is prevented.   
     
     
         7 . The reagent of  claim 6 , wherein the reagent contains polyanion or its salt at 0.3 to 5 percent by weight, dextran at 0.3 to 5 percent by weight, cyclodextrin at 0.1 to 5 percent by weight, polyethylene glycol at 0.5 to 5 percent by weight, or glycerol at 5 to 40 percent by weight. 
     
     
         8 . The reagent of  claim 6 , wherein the polyanion or its salt is a water-soluble, sulfate group-containing polymer compound. 
     
     
         9 . The reagent of  claim 8 , wherein the polyanion is dextran sulfate or heparin. 
     
     
         10 . The reagent of  claim 6 , wherein the reactive substance-bound microparticle is a colloidal gold particle to which an antibody or antigen is bound. 
     
     
         11 . A reagent kit, comprising the reagent of  claim 6 . 
     
     
         12 . An automated immunoassay method, comprising combining the reagent according to  claim 6  with a sample. 
     
     
         13 . The method of  claim 2 , wherein the polyanion or its salt is a water-soluble, sulfate group-containing polymer compound. 
     
     
         14 . The method of  claim 2 , wherein the reactive substance-bound microparticle is a colloidal gold particle to which an antibody or antigen is bound. 
     
     
         15 . The method of  claim 3 , wherein the reactive substance-bound microparticle is a colloidal gold particle to which an antibody or antigen is bound. 
     
     
         16 . The method of  claim 4 , wherein the reactive substance-bound microparticle is a colloidal gold particle to which an antibody or antigen is bound. 
     
     
         17 . The reagent of  claim 7 , wherein the polyanion or its salt is a water-soluble, sulfate group-containing polymer compound. 
     
     
         18 . The reagent of  claim 7 , wherein the reactive substance-bound microparticle is a colloidal gold particle to which an antibody or antigen is bound. 
     
     
         19 . A reagent kit, comprising the reagent of  claim 7 . 
     
     
         20 . An automated immunoassay method, comprising combining the reagent according to  claim 7  with a sample.